51811520 has 28 divisors (see below), whose sum is σ = 123376944. Its totient is φ = 20724480.

The previous prime is 51811519. The next prime is 51811523. The reversal of 51811520 is 2511815.

It is not an unprimeable number, because it can be changed into a prime (51811523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80636 + ... + 81275.

Almost surely, 2^51811520 is an apocalyptic number.

It is an amenable number.

51811520 is an abundant number, since it is smaller than the sum of its proper divisors (71565424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51811520 is a wasteful number, since it uses less digits than its factorization.

51811520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161928 (or 161918 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 51811520 is about 7198.0219505083. The cubic root of 51811520 is about 372.7996058129.

The spelling of 51811520 in words is "fifty-one million, eight hundred eleven thousand, five hundred twenty".